Abstract-Effect of inhibition on apoptosis of bEnd.3 cells induced by terahertz radiation

Pengfei Xie, Xingxing Lu, Yiwen Sun,

https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10826/108260N/Effect-of-inhibition-on-apoptosis-of-bEnd3-cells-induced-by/10.1117/12.2500304.full

The use of terahertz radiation in various fields such as biology and medicine is increasing every year. Meanwhile, people are increasingly concerned about the mechanism on the interaction between terahertz radiation and biological system. In this study, we evaluated the effect of the cellular response of bEnd.3 which exposing to the terahertz radiation in the range of 0.1-3.5 THz. We collected the spectral data of cells during the irradiation with a temperature of 20.6°C and a relative humidity of 5%. Meanwhile, the apoptosis of cell was assessed by Annexin V-FITC/PI kit. As a result, the apoptosis of cells were inhibited from 0 and 6 hours after terahertz irradiation and promoted at 12 hours after irradiation. Moreover, we also calculated the complex dielectric constant of bEnd.3 cells at different exposures. The results demonstrate that the dielectric loss of cells showed a slight decrease with the increase of exposure in the range of 0.2-1.4 THz.

© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Abstract-Quantitative characterization of bovine serum albumin thin-films using terahertz spectroscopy and machine learning methods

Yiwen Sun, Pengju Du, Xingxing Lu, Pengfei Xie, Zhengfang Qian, Shuting Fan, and Zexuan Zhu

https://www.osapublishing.org/boe/abstract.cfm?uri=boe-9-7-2917

The development of new spectral analysis methods in bio thin-film detection has generated intense interest in terahertz (THz) spectroscopy and its application in a wide range of fields. In this paper, it is the first time that machine learning methods are applied to the quantitative characterization of bovine serum albumin (BSA) deposited thin-films detected by terahertz time-domain spectroscopy. The spectra data of BSA thin-films prepared by solutions with concentrations ranging from 0.5 to 35 mg/ml are analyzed using the support vector regression method to learn the underlying model of the frequency against the target concentration. The learned mode successfully predicts the concentrations of the unknown test samples with a coefficient of determination R2 = 0.97932. Furthermore, aiming to identify the relevance of each frequency to the concentration, the maximal information coefficient statistical analysis is used and the three most discriminating frequencies in THz frequency are identified at 1.2, 1.1 and 0.5 THz respectively, which means a good prediction for BSA concentration can be achieved by using the top three relevant frequencies. Moreover, the top discriminating frequencies are in good agreement with the frequencies predicted by a long-wavelength elastic vibration model for BSA protein.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Investigate the effects of EG doping PEDOT/PSS on transmission and anti-reflection properties using terahertz pulsed spectroscopy

Yiwen Sun, Shengxin Yang, Pengju Du, Fei Yan, Junle Qu, Zexuan Zhu, Jian Zuo, and Cunlin Zhang

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-25-3-1723&origin=search

The conductivity of poly(3,4-ethylene dioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) is significantly enhanced on adding some organic solvent such as ethylene glycol (EG). In this paper, the optoelectronic properties of EG doped PEDOT/PSS on transmission and anti-reflection effects are investigated in detail by terahertz time domain spectroscopy (THz-TDS). The transmission line circuit theory gives us an insight into the THz transmission mechanisms of the main and second pulses. In particular, we show that the conductivities of 10% EG doped PEDOT/PSS are nearly frequency independent from 0.3 to 1.5 THz. To demonstrate applications of this property, we design and fabricate broadband terahertz neutral density filters and anti-reflection coatings based on 10% EG doped PEDOT/PSS thin films with varying thickness. Our measurements highlight the capability of THz-TDS to characterize the conductivity of EG doped PEDOT/PSS, which is essential for broadband optoelectronic devices in THz region.

© 2017 Optical Society of America

Abstract-Label-free detection and characterization of the binding of hemagglutinin protein and broadly neutralizing monoclonal antibodies using terahertz spectroscopy

Yiwen Sun ; Junlan Zhong ; Cunlin Zhang ; Jian Zuo ; Emma Pickwell-MacPherson

http://biomedicaloptics.spiedigitallibrary.org/article.aspx?articleid=2203081&resultClick=1

Yiwen Sun, Junlan Zhong

Shenzhen University, School of Medicine, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Department of Biomedical Engineering, Shenzhen 518060, China

Cunlin Zhang, Jian Zuo

Capital Normal University, Department of Physics, Beijing 100037, China

Emma Pickwell-MacPherson

Chinese University of Hong Kong, Department of Electronic Engineering, Shatin, Hong Kong

J. Biomed. Opt. 20(3), 037006 (Mar 10, 2015). doi:10.1117/1.JBO.20.3.037006

Abstract.  Hemagglutinin (HA) is the main surface glycoprotein of the influenza A virus. The H9N2 subtype influenza A virus is recognized as the most possible pandemic strain as it has crossed the species barrier, infecting swine and humans. We use terahertz spectroscopy to study the hydration shell formation around H9 subtype influenza A virus’s HA protein (H9 HA) as well as the detection of antigen binding of H9 HA with the broadly neutralizing monoclonal antibody. We observe a remarkable concentration dependent nonlinear response of the H9 HA, which reveals the formation process of the hydration shell around H9 HA molecules. Furthermore, we show that terahertz dielectric properties of the H9 HA are strongly affected by the presence of the monoclonal antibody F10 and that the terahertz dielectric loss tangent can be used to detect the antibody binding at lower concentrations than the standard ELISA test.

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